1. Field of the Invention
The present invention relates to an exercise apparatus having arm and leg supporting members that travel in closed paths, and more specifically to an exercise apparatus that senses user forces applied to the exercise apparatus and automatically adjusts dimensions of the closed paths in response to the sensed user forces.
2. Description of Related Art
Many exercise apparatuses facilitate both arm movements and leg movements. Examples of such equipment include elliptical exercise apparatuses (U.S. Pat. Nos. 5,242,343, 5,423,729, 5,540,637, 5,725,457, and 5,792,026); free form exercise apparatus (U.S. Pat. Nos. 5,290,211 and 5,401,226); rider exercise apparatus (U.S. Pat. Nos. 2,603,486, 5,695,434, and 5,997,446); glider/strider exercise apparatus (U.S. Pat. Nos. 4,940,233 and 5,795,268); stepper exercise apparatus (U.S. Pat. No. 4,934,690); bicycle exercise apparatus (U.S. Pat. Nos. 4,188,030 and 4,509,742); and various other, miscellaneous exercise apparatus (U.S. Pat. Nos. 4,869,494 and 5,039,088). These patents are incorporated herein by reference as examples of suitable applications for the present invention. Generally speaking, the foregoing exercise apparatuses have arm-supporting members and leg-supporting members synchronized to facilitate a coordinated “total body” exercise motion. Synchronized motion makes the equipment relatively easy to use but the perceived quality of exercise tends to exceed the actual quality of exercise because the arms typically perform very little work. In industry terminology, the arms are generally “along for the ride.” Some exercise apparatuses have been developed to provide independent upper body exercise and lower body exercise. One notable example is the NordicTrack ski exercise apparatus (U.S. Pat. No. 4,728,102) but many people consider such exercise apparatuses relatively difficult to use, due to the independent nature of the arm motions and the leg motions. Recognizing that each of the foregoing types of total body exercise apparatus suffers certain shortcomings, room for improvement remains with respect to total body exercise apparatuses.